Three dimensional measurement systems based on computing the triangular intersection of projected light viewed from an angle by a light sensitive detector requires sharply imaged light and sufficient reflected light to exceed the detector noise level and ambient light level. On the projector side of the system, the sharply imaged light has to remain well focused over the depth for which the measurements are to be made. A projected narrow light beam or light plane provides measurements only along the narrow light path, thereby limiting the data obtainable. By scanning the light beam or plane, data can be obtained over a surface without moving the system. In scanning the light beam or plane, however, sharp imaging on the detector side of the system is adversely affected. This stems from the fact that a lens is used to image the reflected light onto the detector and the depth of focus is not very large when using a large lens aperture. The large aperture is needed to gather sufficient light for reliable detection. However, moving the light beam or plane defocuses the received light leading to imprecise measurement and lower light intensity, and this reduces measurement reliability. Increasing the projected light intensity is often not possible for reasons of safety or device limitations. A tradeoff therefore has had to be made between the various system parameters to obtain the optimal results within the given constraints.